1. Field of the Invention
The present invention relates to an electric spindle motor and a recording disk driving apparatus having the spindle motor.
2. Background Art
Hitherto, a spindle motor having a fluid dynamic pressure bearing in which oil is interposed in a small clearance between a shaft and a sleeve is used for various electronic devices such as a recording disk driving apparatus. In such a spindle motor, for example, to prevent a rotor having a shaft from being detached from a sleeve, a detachment preventing (regulating) structure is constructed between the inner portion of the rotor and the outer portion of the sleeve. By such a detachment preventing structure, the rotor is prevented from moving so as to be apart from the sleeve, and reduction in the thickness of the spindle motor is realized.
In recent years, the recording disk driving apparatus is being used as a recording apparatus of a portable electronic equipment. Consequently, the spindle motor for use in a recording disk driving apparatus is also requested to be smaller and thinner. Attempts are made to address the request by reducing the size of each of members constructing the spindle motor.
To manufacture such a smaller and thinner spindle motor, however, smaller members have to be handled, so that it is difficult to efficiently manufacture a spindle motor.